linux/drivers/net/irda/stir4200.c
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   1/*****************************************************************************
   2*
   3* Filename:      stir4200.c
   4* Version:       0.4
   5* Description:   Irda SigmaTel USB Dongle
   6* Status:        Experimental
   7* Author:        Stephen Hemminger <shemminger@osdl.org>
   8*
   9*       Based on earlier driver by Paul Stewart <stewart@parc.com>
  10*
  11*       Copyright (C) 2000, Roman Weissgaerber <weissg@vienna.at>
  12*       Copyright (C) 2001, Dag Brattli <dag@brattli.net>
  13*       Copyright (C) 2001, Jean Tourrilhes <jt@hpl.hp.com>
  14*       Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
  15*
  16*       This program is free software; you can redistribute it and/or modify
  17*       it under the terms of the GNU General Public License as published by
  18*       the Free Software Foundation; either version 2 of the License.
  19*
  20*       This program is distributed in the hope that it will be useful,
  21*       but WITHOUT ANY WARRANTY; without even the implied warranty of
  22*       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23*       GNU General Public License for more details.
  24*
  25*       You should have received a copy of the GNU General Public License
  26*       along with this program; if not, write to the Free Software
  27*       Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  28*
  29*****************************************************************************/
  30
  31/*
  32 * This dongle does no framing, and requires polling to receive the
  33 * data.  The STIr4200 has bulk in and out endpoints just like
  34 * usr-irda devices, but the data it sends and receives is raw; like
  35 * irtty, it needs to call the wrap and unwrap functions to add and
  36 * remove SOF/BOF and escape characters to/from the frame.
  37 */
  38
  39#include <linux/module.h>
  40#include <linux/moduleparam.h>
  41
  42#include <linux/kernel.h>
  43#include <linux/types.h>
  44#include <linux/init.h>
  45#include <linux/time.h>
  46#include <linux/skbuff.h>
  47#include <linux/netdevice.h>
  48#include <linux/slab.h>
  49#include <linux/delay.h>
  50#include <linux/usb.h>
  51#include <linux/crc32.h>
  52#include <linux/kthread.h>
  53#include <linux/freezer.h>
  54#include <net/irda/irda.h>
  55#include <net/irda/irda_device.h>
  56#include <net/irda/wrapper.h>
  57#include <net/irda/crc.h>
  58#include <asm/byteorder.h>
  59#include <asm/unaligned.h>
  60
  61MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.org>");
  62MODULE_DESCRIPTION("IrDA-USB Dongle Driver for SigmaTel STIr4200");
  63MODULE_LICENSE("GPL");
  64
  65static int qos_mtt_bits = 0x07; /* 1 ms or more */
  66module_param(qos_mtt_bits, int, 0);
  67MODULE_PARM_DESC(qos_mtt_bits, "Minimum Turn Time");
  68
  69static int rx_sensitivity = 1;  /* FIR 0..4, SIR 0..6 */
  70module_param(rx_sensitivity, int, 0);
  71MODULE_PARM_DESC(rx_sensitivity, "Set Receiver sensitivity (0-6, 0 is most sensitive)");
  72
  73static int tx_power = 0;        /* 0 = highest ... 3 = lowest */
  74module_param(tx_power, int, 0);
  75MODULE_PARM_DESC(tx_power, "Set Transmitter power (0-3, 0 is highest power)");
  76
  77#define STIR_IRDA_HEADER        4
  78#define CTRL_TIMEOUT            100        /* milliseconds */
  79#define TRANSMIT_TIMEOUT        200        /* milliseconds */
  80#define STIR_FIFO_SIZE          4096
  81#define FIFO_REGS_SIZE          3
  82
  83enum FirChars {
  84        FIR_CE   = 0x7d,
  85        FIR_XBOF = 0x7f,
  86        FIR_EOF  = 0x7e,
  87};
  88
  89enum StirRequests {
  90        REQ_WRITE_REG =         0x00,
  91        REQ_READ_REG =          0x01,
  92        REQ_READ_ROM =          0x02,
  93        REQ_WRITE_SINGLE =      0x03,
  94};
  95
  96/* Register offsets */
  97enum StirRegs {
  98        REG_RSVD=0,
  99        REG_MODE,
 100        REG_PDCLK,
 101        REG_CTRL1,
 102        REG_CTRL2,
 103        REG_FIFOCTL,
 104        REG_FIFOLSB,
 105        REG_FIFOMSB,
 106        REG_DPLL,
 107        REG_IRDIG,
 108        REG_TEST=15,
 109};
 110
 111enum StirModeMask {
 112        MODE_FIR = 0x80,
 113        MODE_SIR = 0x20,
 114        MODE_ASK = 0x10,
 115        MODE_FASTRX = 0x08,
 116        MODE_FFRSTEN = 0x04,
 117        MODE_NRESET = 0x02,
 118        MODE_2400 = 0x01,
 119};
 120
 121enum StirPdclkMask {
 122        PDCLK_4000000 = 0x02,
 123        PDCLK_115200 = 0x09,
 124        PDCLK_57600 = 0x13,
 125        PDCLK_38400 = 0x1D,
 126        PDCLK_19200 = 0x3B,
 127        PDCLK_9600 = 0x77,
 128        PDCLK_2400 = 0xDF,
 129};
 130
 131enum StirCtrl1Mask {
 132        CTRL1_SDMODE = 0x80,
 133        CTRL1_RXSLOW = 0x40,
 134        CTRL1_TXPWD = 0x10,
 135        CTRL1_RXPWD = 0x08,
 136        CTRL1_SRESET = 0x01,
 137};
 138
 139enum StirCtrl2Mask {
 140        CTRL2_SPWIDTH = 0x08,
 141        CTRL2_REVID = 0x03,
 142};
 143
 144enum StirFifoCtlMask {
 145        FIFOCTL_DIR = 0x10,
 146        FIFOCTL_CLR = 0x08,
 147        FIFOCTL_EMPTY = 0x04,
 148};
 149
 150enum StirDiagMask {
 151        IRDIG_RXHIGH = 0x80,
 152        IRDIG_RXLOW = 0x40,
 153};
 154
 155enum StirTestMask {
 156        TEST_PLLDOWN = 0x80,
 157        TEST_LOOPIR = 0x40,
 158        TEST_LOOPUSB = 0x20,
 159        TEST_TSTENA = 0x10,
 160        TEST_TSTOSC = 0x0F,
 161};
 162
 163struct stir_cb {
 164        struct usb_device *usbdev;      /* init: probe_irda */
 165        struct net_device *netdev;      /* network layer */
 166        struct irlap_cb   *irlap;       /* The link layer we are binded to */
 167
 168        struct qos_info   qos;
 169        unsigned          speed;        /* Current speed */
 170
 171        struct task_struct *thread;     /* transmit thread */
 172
 173        struct sk_buff    *tx_pending;
 174        void              *io_buf;      /* transmit/receive buffer */
 175        __u8              *fifo_status;
 176
 177        iobuff_t          rx_buff;      /* receive unwrap state machine */
 178        struct timeval    rx_time;
 179        int               receiving;
 180        struct urb       *rx_urb;
 181};
 182
 183
 184/* These are the currently known USB ids */
 185static struct usb_device_id dongles[] = {
 186    /* SigmaTel, Inc,  STIr4200 IrDA/USB Bridge */
 187    { USB_DEVICE(0x066f, 0x4200) },
 188    { }
 189};
 190
 191MODULE_DEVICE_TABLE(usb, dongles);
 192
 193/* Send control message to set dongle register */
 194static int write_reg(struct stir_cb *stir, __u16 reg, __u8 value)
 195{
 196        struct usb_device *dev = stir->usbdev;
 197
 198        pr_debug("%s: write reg %d = 0x%x\n",
 199                 stir->netdev->name, reg, value);
 200        return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
 201                               REQ_WRITE_SINGLE,
 202                               USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_DEVICE,
 203                               value, reg, NULL, 0,
 204                               CTRL_TIMEOUT);
 205}
 206
 207/* Send control message to read multiple registers */
 208static inline int read_reg(struct stir_cb *stir, __u16 reg,
 209                    __u8 *data, __u16 count)
 210{
 211        struct usb_device *dev = stir->usbdev;
 212
 213        return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 214                               REQ_READ_REG,
 215                               USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 216                               0, reg, data, count,
 217                               CTRL_TIMEOUT);
 218}
 219
 220static inline int isfir(u32 speed)
 221{
 222        return speed == 4000000;
 223}
 224
 225/*
 226 * Prepare a FIR IrDA frame for transmission to the USB dongle.  The
 227 * FIR transmit frame is documented in the datasheet.  It consists of
 228 * a two byte 0x55 0xAA sequence, two little-endian length bytes, a
 229 * sequence of exactly 16 XBOF bytes of 0x7E, two BOF bytes of 0x7E,
 230 * then the data escaped as follows:
 231 *
 232 *    0x7D -> 0x7D 0x5D
 233 *    0x7E -> 0x7D 0x5E
 234 *    0x7F -> 0x7D 0x5F
 235 *
 236 * Then, 4 bytes of little endian (stuffed) FCS follow, then two
 237 * trailing EOF bytes of 0x7E.
 238 */
 239static inline __u8 *stuff_fir(__u8 *p, __u8 c)
 240{
 241        switch(c) {
 242        case 0x7d:
 243        case 0x7e:
 244        case 0x7f:
 245                *p++ = 0x7d;
 246                c ^= IRDA_TRANS;
 247                /* fall through */
 248        default:
 249                *p++ = c;
 250        }
 251        return p;
 252}
 253
 254/* Take raw data in skb and put it wrapped into buf */
 255static unsigned wrap_fir_skb(const struct sk_buff *skb, __u8 *buf)
 256{
 257        __u8 *ptr = buf;
 258        __u32 fcs = ~(crc32_le(~0, skb->data, skb->len));
 259        __u16 wraplen;
 260        int i;
 261
 262        /* Header */
 263        buf[0] = 0x55;
 264        buf[1] = 0xAA;
 265
 266        ptr = buf + STIR_IRDA_HEADER;
 267        memset(ptr, 0x7f, 16);
 268        ptr += 16;
 269
 270        /* BOF */
 271        *ptr++  = 0x7e;
 272        *ptr++  = 0x7e;
 273
 274        /* Address / Control / Information */
 275        for (i = 0; i < skb->len; i++)
 276                ptr = stuff_fir(ptr, skb->data[i]);
 277
 278        /* FCS */
 279        ptr = stuff_fir(ptr, fcs & 0xff);
 280        ptr = stuff_fir(ptr, (fcs >> 8) & 0xff);
 281        ptr = stuff_fir(ptr, (fcs >> 16) & 0xff);
 282        ptr = stuff_fir(ptr, (fcs >> 24) & 0xff);
 283
 284        /* EOFs */
 285        *ptr++ = 0x7e;
 286        *ptr++ = 0x7e;
 287
 288        /* Total length, minus the header */
 289        wraplen = (ptr - buf) - STIR_IRDA_HEADER;
 290        buf[2] = wraplen & 0xff;
 291        buf[3] = (wraplen >> 8) & 0xff;
 292
 293        return wraplen + STIR_IRDA_HEADER;
 294}
 295
 296static unsigned wrap_sir_skb(struct sk_buff *skb, __u8 *buf)
 297{
 298        __u16 wraplen;
 299
 300        wraplen = async_wrap_skb(skb, buf + STIR_IRDA_HEADER,
 301                                 STIR_FIFO_SIZE - STIR_IRDA_HEADER);
 302        buf[0] = 0x55;
 303        buf[1] = 0xAA;
 304        buf[2] = wraplen & 0xff;
 305        buf[3] = (wraplen >> 8) & 0xff;
 306
 307        return wraplen + STIR_IRDA_HEADER;
 308}
 309
 310/*
 311 * Frame is fully formed in the rx_buff so check crc
 312 * and pass up to irlap
 313 * setup for next receive
 314 */
 315static void fir_eof(struct stir_cb *stir)
 316{
 317        iobuff_t *rx_buff = &stir->rx_buff;
 318        int len = rx_buff->len - 4;
 319        struct sk_buff *skb, *nskb;
 320        __u32 fcs;
 321
 322        if (unlikely(len <= 0)) {
 323                pr_debug("%s: short frame len %d\n",
 324                         stir->netdev->name, len);
 325
 326                ++stir->netdev->stats.rx_errors;
 327                ++stir->netdev->stats.rx_length_errors;
 328                return;
 329        }
 330
 331        fcs = ~(crc32_le(~0, rx_buff->data, len));
 332        if (fcs != get_unaligned_le32(rx_buff->data + len)) {
 333                pr_debug("crc error calc 0x%x len %d\n", fcs, len);
 334                stir->netdev->stats.rx_errors++;
 335                stir->netdev->stats.rx_crc_errors++;
 336                return;
 337        }
 338
 339        /* if frame is short then just copy it */
 340        if (len < IRDA_RX_COPY_THRESHOLD) {
 341                nskb = dev_alloc_skb(len + 1);
 342                if (unlikely(!nskb)) {
 343                        ++stir->netdev->stats.rx_dropped;
 344                        return;
 345                }
 346                skb_reserve(nskb, 1);
 347                skb = nskb;
 348                skb_copy_to_linear_data(nskb, rx_buff->data, len);
 349        } else {
 350                nskb = dev_alloc_skb(rx_buff->truesize);
 351                if (unlikely(!nskb)) {
 352                        ++stir->netdev->stats.rx_dropped;
 353                        return;
 354                }
 355                skb_reserve(nskb, 1);
 356                skb = rx_buff->skb;
 357                rx_buff->skb = nskb;
 358                rx_buff->head = nskb->data;
 359        }
 360
 361        skb_put(skb, len);
 362
 363        skb_reset_mac_header(skb);
 364        skb->protocol = htons(ETH_P_IRDA);
 365        skb->dev = stir->netdev;
 366
 367        netif_rx(skb);
 368
 369        stir->netdev->stats.rx_packets++;
 370        stir->netdev->stats.rx_bytes += len;
 371
 372        rx_buff->data = rx_buff->head;
 373        rx_buff->len = 0;
 374}
 375
 376/* Unwrap FIR stuffed data and bump it to IrLAP */
 377static void stir_fir_chars(struct stir_cb *stir,
 378                            const __u8 *bytes, int len)
 379{
 380        iobuff_t *rx_buff = &stir->rx_buff;
 381        int     i;
 382
 383        for (i = 0; i < len; i++) {
 384                __u8    byte = bytes[i];
 385
 386                switch(rx_buff->state) {
 387                case OUTSIDE_FRAME:
 388                        /* ignore garbage till start of frame */
 389                        if (unlikely(byte != FIR_EOF))
 390                                continue;
 391                        /* Now receiving frame */
 392                        rx_buff->state = BEGIN_FRAME;
 393
 394                        /* Time to initialize receive buffer */
 395                        rx_buff->data = rx_buff->head;
 396                        rx_buff->len = 0;
 397                        continue;
 398
 399                case LINK_ESCAPE:
 400                        if (byte == FIR_EOF) {
 401                                pr_debug("%s: got EOF after escape\n",
 402                                         stir->netdev->name);
 403                                goto frame_error;
 404                        }
 405                        rx_buff->state = INSIDE_FRAME;
 406                        byte ^= IRDA_TRANS;
 407                        break;
 408
 409                case BEGIN_FRAME:
 410                        /* ignore multiple BOF/EOF */
 411                        if (byte == FIR_EOF)
 412                                continue;
 413                        rx_buff->state = INSIDE_FRAME;
 414                        rx_buff->in_frame = TRUE;
 415
 416                        /* fall through */
 417                case INSIDE_FRAME:
 418                        switch(byte) {
 419                        case FIR_CE:
 420                                rx_buff->state = LINK_ESCAPE;
 421                                continue;
 422                        case FIR_XBOF:
 423                                /* 0x7f is not used in this framing */
 424                                pr_debug("%s: got XBOF without escape\n",
 425                                         stir->netdev->name);
 426                                goto frame_error;
 427                        case FIR_EOF:
 428                                rx_buff->state = OUTSIDE_FRAME;
 429                                rx_buff->in_frame = FALSE;
 430                                fir_eof(stir);
 431                                continue;
 432                        }
 433                        break;
 434                }
 435
 436                /* add byte to rx buffer */
 437                if (unlikely(rx_buff->len >= rx_buff->truesize)) {
 438                        pr_debug("%s: fir frame exceeds %d\n",
 439                                 stir->netdev->name, rx_buff->truesize);
 440                        ++stir->netdev->stats.rx_over_errors;
 441                        goto error_recovery;
 442                }
 443
 444                rx_buff->data[rx_buff->len++] = byte;
 445                continue;
 446
 447        frame_error:
 448                ++stir->netdev->stats.rx_frame_errors;
 449
 450        error_recovery:
 451                ++stir->netdev->stats.rx_errors;
 452                rx_buff->state = OUTSIDE_FRAME;
 453                rx_buff->in_frame = FALSE;
 454        }
 455}
 456
 457/* Unwrap SIR stuffed data and bump it up to IrLAP */
 458static void stir_sir_chars(struct stir_cb *stir,
 459                            const __u8 *bytes, int len)
 460{
 461        int i;
 462
 463        for (i = 0; i < len; i++)
 464                async_unwrap_char(stir->netdev, &stir->netdev->stats,
 465                                  &stir->rx_buff, bytes[i]);
 466}
 467
 468static inline void unwrap_chars(struct stir_cb *stir,
 469                                const __u8 *bytes, int length)
 470{
 471        if (isfir(stir->speed))
 472                stir_fir_chars(stir, bytes, length);
 473        else
 474                stir_sir_chars(stir, bytes, length);
 475}
 476
 477/* Mode parameters for each speed */
 478static const struct {
 479        unsigned speed;
 480        __u8 pdclk;
 481} stir_modes[] = {
 482        { 2400,    PDCLK_2400 },
 483        { 9600,    PDCLK_9600 },
 484        { 19200,   PDCLK_19200 },
 485        { 38400,   PDCLK_38400 },
 486        { 57600,   PDCLK_57600 },
 487        { 115200,  PDCLK_115200 },
 488        { 4000000, PDCLK_4000000 },
 489};
 490
 491
 492/*
 493 * Setup chip for speed.
 494 *  Called at startup to initialize the chip
 495 *  and on speed changes.
 496 *
 497 * Note: Write multiple registers doesn't appear to work
 498 */
 499static int change_speed(struct stir_cb *stir, unsigned speed)
 500{
 501        int i, err;
 502        __u8 mode;
 503
 504        for (i = 0; i < ARRAY_SIZE(stir_modes); ++i) {
 505                if (speed == stir_modes[i].speed)
 506                        goto found;
 507        }
 508
 509        dev_warn(&stir->netdev->dev, "invalid speed %d\n", speed);
 510        return -EINVAL;
 511
 512 found:
 513        pr_debug("speed change from %d to %d\n", stir->speed, speed);
 514
 515        /* Reset modulator */
 516        err = write_reg(stir, REG_CTRL1, CTRL1_SRESET);
 517        if (err)
 518                goto out;
 519
 520        /* Undocumented magic to tweak the DPLL */
 521        err = write_reg(stir, REG_DPLL, 0x15);
 522        if (err)
 523                goto out;
 524
 525        /* Set clock */
 526        err = write_reg(stir, REG_PDCLK, stir_modes[i].pdclk);
 527        if (err)
 528                goto out;
 529
 530        mode = MODE_NRESET | MODE_FASTRX;
 531        if (isfir(speed))
 532                mode |= MODE_FIR | MODE_FFRSTEN;
 533        else
 534                mode |= MODE_SIR;
 535
 536        if (speed == 2400)
 537                mode |= MODE_2400;
 538
 539        err = write_reg(stir, REG_MODE, mode);
 540        if (err)
 541                goto out;
 542
 543        /* This resets TEMIC style transceiver if any. */
 544        err = write_reg(stir, REG_CTRL1,
 545                        CTRL1_SDMODE | (tx_power & 3) << 1);
 546        if (err)
 547                goto out;
 548
 549        err = write_reg(stir, REG_CTRL1, (tx_power & 3) << 1);
 550        if (err)
 551                goto out;
 552
 553        /* Reset sensitivity */
 554        err = write_reg(stir, REG_CTRL2, (rx_sensitivity & 7) << 5);
 555 out:
 556        stir->speed = speed;
 557        return err;
 558}
 559
 560/*
 561 * Called from net/core when new frame is available.
 562 */
 563static netdev_tx_t stir_hard_xmit(struct sk_buff *skb,
 564                                        struct net_device *netdev)
 565{
 566        struct stir_cb *stir = netdev_priv(netdev);
 567
 568        netif_stop_queue(netdev);
 569
 570        /* the IRDA wrapping routines don't deal with non linear skb */
 571        SKB_LINEAR_ASSERT(skb);
 572
 573        skb = xchg(&stir->tx_pending, skb);
 574        wake_up_process(stir->thread);
 575        
 576        /* this should never happen unless stop/wakeup problem */
 577        if (unlikely(skb)) {
 578                WARN_ON(1);
 579                dev_kfree_skb(skb);
 580        }
 581
 582        return NETDEV_TX_OK;
 583}
 584
 585/*
 586 * Wait for the transmit FIFO to have space for next data
 587 *
 588 * If space < 0 then wait till FIFO completely drains.
 589 * FYI: can take up to 13 seconds at 2400baud.
 590 */
 591static int fifo_txwait(struct stir_cb *stir, int space)
 592{
 593        int err;
 594        unsigned long count, status;
 595        unsigned long prev_count = 0x1fff;
 596
 597        /* Read FIFO status and count */
 598        for (;; prev_count = count) {
 599                err = read_reg(stir, REG_FIFOCTL, stir->fifo_status, 
 600                                   FIFO_REGS_SIZE);
 601                if (unlikely(err != FIFO_REGS_SIZE)) {
 602                        dev_warn(&stir->netdev->dev,
 603                                 "FIFO register read error: %d\n", err);
 604
 605                        return err;
 606                }
 607
 608                status = stir->fifo_status[0];
 609                count = (unsigned)(stir->fifo_status[2] & 0x1f) << 8 
 610                        | stir->fifo_status[1];
 611
 612                pr_debug("fifo status 0x%lx count %lu\n", status, count);
 613
 614                /* is fifo receiving already, or empty */
 615                if (!(status & FIFOCTL_DIR) ||
 616                    (status & FIFOCTL_EMPTY))
 617                        return 0;
 618
 619                if (signal_pending(current))
 620                        return -EINTR;
 621
 622                /* shutting down? */
 623                if (!netif_running(stir->netdev) ||
 624                    !netif_device_present(stir->netdev))
 625                        return -ESHUTDOWN;
 626
 627                /* only waiting for some space */
 628                if (space >= 0 && STIR_FIFO_SIZE - 4 > space + count)
 629                        return 0;
 630
 631                /* queue confused */
 632                if (prev_count < count)
 633                        break;
 634
 635                /* estimate transfer time for remaining chars */
 636                msleep((count * 8000) / stir->speed);
 637        }
 638                        
 639        err = write_reg(stir, REG_FIFOCTL, FIFOCTL_CLR);
 640        if (err) 
 641                return err;
 642        err = write_reg(stir, REG_FIFOCTL, 0);
 643        if (err)
 644                return err;
 645
 646        return 0;
 647}
 648
 649
 650/* Wait for turnaround delay before starting transmit.  */
 651static void turnaround_delay(const struct stir_cb *stir, long us)
 652{
 653        long ticks;
 654        struct timeval now;
 655
 656        if (us <= 0)
 657                return;
 658
 659        do_gettimeofday(&now);
 660        if (now.tv_sec - stir->rx_time.tv_sec > 0)
 661                us -= USEC_PER_SEC;
 662        us -= now.tv_usec - stir->rx_time.tv_usec;
 663        if (us < 10)
 664                return;
 665
 666        ticks = us / (1000000 / HZ);
 667        if (ticks > 0)
 668                schedule_timeout_interruptible(1 + ticks);
 669        else
 670                udelay(us);
 671}
 672
 673/*
 674 * Start receiver by submitting a request to the receive pipe.
 675 * If nothing is available it will return after rx_interval.
 676 */
 677static int receive_start(struct stir_cb *stir)
 678{
 679        /* reset state */
 680        stir->receiving = 1;
 681
 682        stir->rx_buff.in_frame = FALSE;
 683        stir->rx_buff.state = OUTSIDE_FRAME;
 684
 685        stir->rx_urb->status = 0;
 686        return usb_submit_urb(stir->rx_urb, GFP_KERNEL);
 687}
 688
 689/* Stop all pending receive Urb's */
 690static void receive_stop(struct stir_cb *stir)
 691{
 692        stir->receiving = 0;
 693        usb_kill_urb(stir->rx_urb);
 694
 695        if (stir->rx_buff.in_frame) 
 696                stir->netdev->stats.collisions++;
 697}
 698/*
 699 * Wrap data in socket buffer and send it.
 700 */
 701static void stir_send(struct stir_cb *stir, struct sk_buff *skb)
 702{
 703        unsigned wraplen;
 704        int first_frame = 0;
 705
 706        /* if receiving, need to turnaround */
 707        if (stir->receiving) {
 708                receive_stop(stir);
 709                turnaround_delay(stir, irda_get_mtt(skb));
 710                first_frame = 1;
 711        }
 712
 713        if (isfir(stir->speed))
 714                wraplen = wrap_fir_skb(skb, stir->io_buf);
 715        else
 716                wraplen = wrap_sir_skb(skb, stir->io_buf);
 717                
 718        /* check for space available in fifo */
 719        if (!first_frame)
 720                fifo_txwait(stir, wraplen);
 721
 722        stir->netdev->stats.tx_packets++;
 723        stir->netdev->stats.tx_bytes += skb->len;
 724        stir->netdev->trans_start = jiffies;
 725        pr_debug("send %d (%d)\n", skb->len, wraplen);
 726
 727        if (usb_bulk_msg(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1),
 728                         stir->io_buf, wraplen,
 729                         NULL, TRANSMIT_TIMEOUT))
 730                stir->netdev->stats.tx_errors++;
 731}
 732
 733/*
 734 * Transmit state machine thread
 735 */
 736static int stir_transmit_thread(void *arg)
 737{
 738        struct stir_cb *stir = arg;
 739        struct net_device *dev = stir->netdev;
 740        struct sk_buff *skb;
 741
 742        while (!kthread_should_stop()) {
 743#ifdef CONFIG_PM
 744                /* if suspending, then power off and wait */
 745                if (unlikely(freezing(current))) {
 746                        if (stir->receiving)
 747                                receive_stop(stir);
 748                        else
 749                                fifo_txwait(stir, -1);
 750
 751                        write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
 752
 753                        try_to_freeze();
 754
 755                        if (change_speed(stir, stir->speed))
 756                                break;
 757                }
 758#endif
 759
 760                /* if something to send? */
 761                skb = xchg(&stir->tx_pending, NULL);
 762                if (skb) {
 763                        unsigned new_speed = irda_get_next_speed(skb);
 764                        netif_wake_queue(dev);
 765
 766                        if (skb->len > 0)
 767                                stir_send(stir, skb);
 768                        dev_kfree_skb(skb);
 769
 770                        if ((new_speed != -1) && (stir->speed != new_speed)) {
 771                                if (fifo_txwait(stir, -1) ||
 772                                    change_speed(stir, new_speed))
 773                                        break;
 774                        }
 775                        continue;
 776                }
 777
 778                /* nothing to send? start receiving */
 779                if (!stir->receiving &&
 780                    irda_device_txqueue_empty(dev)) {
 781                        /* Wait otherwise chip gets confused. */
 782                        if (fifo_txwait(stir, -1))
 783                                break;
 784
 785                        if (unlikely(receive_start(stir))) {
 786                                if (net_ratelimit())
 787                                        dev_info(&dev->dev,
 788                                                 "%s: receive usb submit failed\n",
 789                                                 stir->netdev->name);
 790                                stir->receiving = 0;
 791                                msleep(10);
 792                                continue;
 793                        }
 794                }
 795
 796                /* sleep if nothing to send */
 797                set_current_state(TASK_INTERRUPTIBLE);
 798                schedule();
 799
 800        }
 801        return 0;
 802}
 803
 804
 805/*
 806 * USB bulk receive completion callback.
 807 * Wakes up every ms (usb round trip) with wrapped 
 808 * data.
 809 */
 810static void stir_rcv_irq(struct urb *urb)
 811{
 812        struct stir_cb *stir = urb->context;
 813        int err;
 814
 815        /* in process of stopping, just drop data */
 816        if (!netif_running(stir->netdev))
 817                return;
 818
 819        /* unlink, shutdown, unplug, other nasties */
 820        if (urb->status != 0) 
 821                return;
 822
 823        if (urb->actual_length > 0) {
 824                pr_debug("receive %d\n", urb->actual_length);
 825                unwrap_chars(stir, urb->transfer_buffer,
 826                             urb->actual_length);
 827                
 828                do_gettimeofday(&stir->rx_time);
 829        }
 830
 831        /* kernel thread is stopping receiver don't resubmit */
 832        if (!stir->receiving)
 833                return;
 834
 835        /* resubmit existing urb */
 836        err = usb_submit_urb(urb, GFP_ATOMIC);
 837
 838        /* in case of error, the kernel thread will restart us */
 839        if (err) {
 840                dev_warn(&stir->netdev->dev, "usb receive submit error: %d\n",
 841                         err);
 842                stir->receiving = 0;
 843                wake_up_process(stir->thread);
 844        }
 845}
 846
 847/*
 848 * Function stir_net_open (dev)
 849 *
 850 *    Network device is taken up. Usually this is done by "ifconfig irda0 up"
 851 */
 852static int stir_net_open(struct net_device *netdev)
 853{
 854        struct stir_cb *stir = netdev_priv(netdev);
 855        int err;
 856        char hwname[16];
 857
 858        err = usb_clear_halt(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1));
 859        if (err)
 860                goto err_out1;
 861        err = usb_clear_halt(stir->usbdev, usb_rcvbulkpipe(stir->usbdev, 2));
 862        if (err)
 863                goto err_out1;
 864
 865        err = change_speed(stir, 9600);
 866        if (err)
 867                goto err_out1;
 868
 869        err = -ENOMEM;
 870
 871        /* Initialize for SIR/FIR to copy data directly into skb.  */
 872        stir->receiving = 0;
 873        stir->rx_buff.truesize = IRDA_SKB_MAX_MTU;
 874        stir->rx_buff.skb = dev_alloc_skb(IRDA_SKB_MAX_MTU);
 875        if (!stir->rx_buff.skb) 
 876                goto err_out1;
 877
 878        skb_reserve(stir->rx_buff.skb, 1);
 879        stir->rx_buff.head = stir->rx_buff.skb->data;
 880        do_gettimeofday(&stir->rx_time);
 881
 882        stir->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 883        if (!stir->rx_urb) 
 884                goto err_out2;
 885
 886        stir->io_buf = kmalloc(STIR_FIFO_SIZE, GFP_KERNEL);
 887        if (!stir->io_buf)
 888                goto err_out3;
 889
 890        usb_fill_bulk_urb(stir->rx_urb, stir->usbdev,
 891                          usb_rcvbulkpipe(stir->usbdev, 2),
 892                          stir->io_buf, STIR_FIFO_SIZE,
 893                          stir_rcv_irq, stir);
 894
 895        stir->fifo_status = kmalloc(FIFO_REGS_SIZE, GFP_KERNEL);
 896        if (!stir->fifo_status) 
 897                goto err_out4;
 898                
 899        /*
 900         * Now that everything should be initialized properly,
 901         * Open new IrLAP layer instance to take care of us...
 902         * Note : will send immediately a speed change...
 903         */
 904        sprintf(hwname, "usb#%d", stir->usbdev->devnum);
 905        stir->irlap = irlap_open(netdev, &stir->qos, hwname);
 906        if (!stir->irlap) {
 907                dev_err(&stir->usbdev->dev, "irlap_open failed\n");
 908                goto err_out5;
 909        }
 910
 911        /** Start kernel thread for transmit.  */
 912        stir->thread = kthread_run(stir_transmit_thread, stir,
 913                                   "%s", stir->netdev->name);
 914        if (IS_ERR(stir->thread)) {
 915                err = PTR_ERR(stir->thread);
 916                dev_err(&stir->usbdev->dev, "unable to start kernel thread\n");
 917                goto err_out6;
 918        }
 919
 920        netif_start_queue(netdev);
 921
 922        return 0;
 923
 924 err_out6:
 925        irlap_close(stir->irlap);
 926 err_out5:
 927        kfree(stir->fifo_status);
 928 err_out4:
 929        kfree(stir->io_buf);
 930 err_out3:
 931        usb_free_urb(stir->rx_urb);
 932 err_out2:
 933        kfree_skb(stir->rx_buff.skb);
 934 err_out1:
 935        return err;
 936}
 937
 938/*
 939 * Function stir_net_close (stir)
 940 *
 941 *    Network device is taken down. Usually this is done by
 942 *    "ifconfig irda0 down"
 943 */
 944static int stir_net_close(struct net_device *netdev)
 945{
 946        struct stir_cb *stir = netdev_priv(netdev);
 947
 948        /* Stop transmit processing */
 949        netif_stop_queue(netdev);
 950
 951        /* Kill transmit thread */
 952        kthread_stop(stir->thread);
 953        kfree(stir->fifo_status);
 954
 955        /* Mop up receive urb's */
 956        usb_kill_urb(stir->rx_urb);
 957        
 958        kfree(stir->io_buf);
 959        usb_free_urb(stir->rx_urb);
 960        kfree_skb(stir->rx_buff.skb);
 961
 962        /* Stop and remove instance of IrLAP */
 963        if (stir->irlap)
 964                irlap_close(stir->irlap);
 965
 966        stir->irlap = NULL;
 967
 968        return 0;
 969}
 970
 971/*
 972 * IOCTLs : Extra out-of-band network commands...
 973 */
 974static int stir_net_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
 975{
 976        struct if_irda_req *irq = (struct if_irda_req *) rq;
 977        struct stir_cb *stir = netdev_priv(netdev);
 978        int ret = 0;
 979
 980        switch (cmd) {
 981        case SIOCSBANDWIDTH: /* Set bandwidth */
 982                if (!capable(CAP_NET_ADMIN))
 983                        return -EPERM;
 984
 985                /* Check if the device is still there */
 986                if (netif_device_present(stir->netdev))
 987                        ret = change_speed(stir, irq->ifr_baudrate);
 988                break;
 989
 990        case SIOCSMEDIABUSY: /* Set media busy */
 991                if (!capable(CAP_NET_ADMIN))
 992                        return -EPERM;
 993
 994                /* Check if the IrDA stack is still there */
 995                if (netif_running(stir->netdev))
 996                        irda_device_set_media_busy(stir->netdev, TRUE);
 997                break;
 998
 999        case SIOCGRECEIVING:
1000                /* Only approximately true */
1001                irq->ifr_receiving = stir->receiving;
1002                break;
1003
1004        default:
1005                ret = -EOPNOTSUPP;
1006        }
1007
1008        return ret;
1009}
1010
1011static const struct net_device_ops stir_netdev_ops = {
1012        .ndo_open       = stir_net_open,
1013        .ndo_stop       = stir_net_close,
1014        .ndo_start_xmit = stir_hard_xmit,
1015        .ndo_do_ioctl   = stir_net_ioctl,
1016};
1017
1018/*
1019 * This routine is called by the USB subsystem for each new device
1020 * in the system. We need to check if the device is ours, and in
1021 * this case start handling it.
1022 * Note : it might be worth protecting this function by a global
1023 * spinlock... Or not, because maybe USB already deal with that...
1024 */
1025static int stir_probe(struct usb_interface *intf,
1026                      const struct usb_device_id *id)
1027{
1028        struct usb_device *dev = interface_to_usbdev(intf);
1029        struct stir_cb *stir = NULL;
1030        struct net_device *net;
1031        int ret = -ENOMEM;
1032
1033        /* Allocate network device container. */
1034        net = alloc_irdadev(sizeof(*stir));
1035        if(!net)
1036                goto err_out1;
1037
1038        SET_NETDEV_DEV(net, &intf->dev);
1039        stir = netdev_priv(net);
1040        stir->netdev = net;
1041        stir->usbdev = dev;
1042
1043        ret = usb_reset_configuration(dev);
1044        if (ret != 0) {
1045                dev_err(&intf->dev, "usb reset configuration failed\n");
1046                goto err_out2;
1047        }
1048
1049        printk(KERN_INFO "SigmaTel STIr4200 IRDA/USB found at address %d, "
1050                "Vendor: %x, Product: %x\n",
1051               dev->devnum, le16_to_cpu(dev->descriptor.idVendor),
1052               le16_to_cpu(dev->descriptor.idProduct));
1053
1054        /* Initialize QoS for this device */
1055        irda_init_max_qos_capabilies(&stir->qos);
1056
1057        /* That's the Rx capability. */
1058        stir->qos.baud_rate.bits       &= IR_2400 | IR_9600 | IR_19200 |
1059                                         IR_38400 | IR_57600 | IR_115200 |
1060                                         (IR_4000000 << 8);
1061        stir->qos.min_turn_time.bits   &= qos_mtt_bits;
1062        irda_qos_bits_to_value(&stir->qos);
1063
1064        /* Override the network functions we need to use */
1065        net->netdev_ops = &stir_netdev_ops;
1066
1067        ret = register_netdev(net);
1068        if (ret != 0)
1069                goto err_out2;
1070
1071        dev_info(&intf->dev, "IrDA: Registered SigmaTel device %s\n",
1072                 net->name);
1073
1074        usb_set_intfdata(intf, stir);
1075
1076        return 0;
1077
1078err_out2:
1079        free_netdev(net);
1080err_out1:
1081        return ret;
1082}
1083
1084/*
1085 * The current device is removed, the USB layer tell us to shut it down...
1086 */
1087static void stir_disconnect(struct usb_interface *intf)
1088{
1089        struct stir_cb *stir = usb_get_intfdata(intf);
1090
1091        if (!stir)
1092                return;
1093
1094        unregister_netdev(stir->netdev);
1095        free_netdev(stir->netdev);
1096
1097        usb_set_intfdata(intf, NULL);
1098}
1099
1100#ifdef CONFIG_PM
1101/* USB suspend, so power off the transmitter/receiver */
1102static int stir_suspend(struct usb_interface *intf, pm_message_t message)
1103{
1104        struct stir_cb *stir = usb_get_intfdata(intf);
1105
1106        netif_device_detach(stir->netdev);
1107        return 0;
1108}
1109
1110/* Coming out of suspend, so reset hardware */
1111static int stir_resume(struct usb_interface *intf)
1112{
1113        struct stir_cb *stir = usb_get_intfdata(intf);
1114
1115        netif_device_attach(stir->netdev);
1116
1117        /* receiver restarted when send thread wakes up */
1118        return 0;
1119}
1120#endif
1121
1122/*
1123 * USB device callbacks
1124 */
1125static struct usb_driver irda_driver = {
1126        .name           = "stir4200",
1127        .probe          = stir_probe,
1128        .disconnect     = stir_disconnect,
1129        .id_table       = dongles,
1130#ifdef CONFIG_PM
1131        .suspend        = stir_suspend,
1132        .resume         = stir_resume,
1133#endif
1134};
1135
1136module_usb_driver(irda_driver);
1137